[Comparative efficiency of externally-irrigated cooled-tip catheter vs. 8-mm-tip catheters in radiofrequency (RF)...

Cooled-tip and 8-mm-tip catheters have been found to be more effective than conventional 4-mm-tip catheters for radiofrequency (RF) ablation of common atrial flutter. The aim of this study was retrospective comparison between cooled-tip and and 8-mm-tip catheters in terms of efficacy and safety of RF ablation in atrial flutter.

Among 148 consecutive patients (pts) referred for common atrial flutter, cavotricuspid ablation was performed with an externally-irrigated cool tip catheter in 100 pts, and with an 8-mm-tip ablation catheter in 48 patients. RF current was applied for 60 seconds at powers of 50 W with the cooled-tip catheter, and in a temperature-controlled mode (65 degrees C/70 W) with the 8-mm-tip catheter, until bidirectional isthmus block was reached, or a total of 35 unsuccessful RF applications were performed.

A higher initial failure rate with 8-mm-tip catheters was significant, compared to the externally-irrigated catheter (18% vs 4% ; p < 0.01). Significant differences were also found in some procedure parameters, such as the number of RF applications (26 +/- 8 vs 35 +/- 10; p < 0.04), fluoroscopy time (11 +/- 15 min vs 27 +/- 10 min; p < 0.01) and total procedure duration (95 +/- 23 min vs 145 +/- 35 min; p < 0.09). No major complications occurred. In a mean follow-up of 30 +/- 11 months atrial flutter recurred only in group treated with 8 mm catheter (10 patients among 48).

In achieving cavotricuspid isthmus block, RF ablation performed through cooled-tip catheters is more efficient than application through 8-mm-tip catheters.